The overall goal of the Neuroimaging Core is to provide the HNRC and collaborative investigators with resources for: 1) in vivo detection of HlV-related brain injury using a broad array of techniques, including structural, functional, metabolic, susceptibility and diffusion weighted MRI, and positron emission tomography (PET);2) post-mortem MR imaging for elucidation of pathological mechanisms that give rise to this damage;3) investigations of the cognitive consequences and neuromedical correlates of these imaging effects;and 4) identification of potential biomarkers for treatment success. In the current funding period, the Core has supported more than 30 projects, resulting in, for example, findings linking detectable CSF HIV viral load at baseline with increases in white matter damage over time;integration of structural, diffusion and histopathological evidence of white matter damage;correlation of reduced white matter tract diffusivity with cognitive impairment;and HIV-associated reductions in cerebral blood flow in lenticular regions. Training and consultation were provided for 31 individuals, resulting in recruiting new investigators to the study of HIV and expanding the use of neuroimaging techniques in national and international settings. Additional collaborations have advanced our goals to expand the range of valid neuroimaging methods available for use in HIV research. Our aims in the proposed renewal period are to: a) provide resources, consultation, and technical assistance for neuroimaging;b) acquire and analyze in vivo and postmortem images to support clinico-anatomic work and pilot studies;c) contribute data and expertise for the development of improved image acquisition and analytic methods for use in HIV;and d) educate research communities regarding promising new imaging approaches for neuroAIDS research. The expanded Core includes vascular and PET amyloid imaging, to advance the study of an aging HIV population. Furthermore, through local, national, and international collaborations, the Core will emphasize method validation and data integration across imaging modalities for use in HIV, approaches that may lead to a better understanding of the CNS effects of HIV infection. This Core will enhance HNRC transdisciplinary aims through close collaboration with the Neurobehavioral, Neuromedical, Neurovirology, and Neurobiology Cores. These broad-ranging functions ensure state of the art support for HNRC-associated studies, close integration with the interdisciplinary HNRC investigative team, and participation in national and international neuroimaging communities.